Tanker



March 23, 1943. J. PREUss l2,314,555

ATTY

J. PREUSS March 23, 1943.

TANKER v Filed July 13, 1942 2 Sheets-Sheet 2 FIG.3

INVENT OR.

JOHN PR EUSS Patented Mar. 23, 1943 UNITED STATES PATENT OFFICE TANKERJohn Preuss, Memphis, Tenn.

Application July 13, 1942, Serial N0. 450,678

8` Claims.

This invention relates to new and useful improvements in vessels,particularly of the type adapted for the transportation of liquids,usually known as tanker-barges, which have iiat bottoms throughout themajor portion of their Width and length. The major diiliculties inliquid transportation in tanker-barges of known types have arisenthrough the difficulty of thoroughly and eiciently emptying the vesselof its cargo at its destination with the consequence that the emptyvessels are returned with a substantial amount of the cargo still onboard. This residual cargo often runs as high as 250 to 300 barrels pervessel, and averages approximately 100 barrels each trip for whichpayment is not made. The carrier is consequently penalized in the amountof cargo which is not removed, and in effect has carried such amount asadditional dead weight, by which the effective capacity of the vessel iscurtailed.

The principal object of this invention is to enable the effective use ofsubstantially the entire cargo capacity of the vessel and to reduce to aminimum, residual cargo which would tend to curtail the effectivecapacity.

It vis customary in vessels of this character to segregate the hold orhull of the vessel into compartments or tanks by transverse tank Wallsand one or more longitudinal tank walls, substantially the entire vesselbeing covered with a deck. Y Each tank is provided with a suction pipe,connected through a header to a suitable pump, which may be carried onthe barge or be on the dock where the barge is unloaded, foraccomplishing unloading or emptying of the tanks. As is well known inpumping practice, a serious problem is that of cavitation (Yor thetendency of the atmosphere tov break through the seal of the surroundingliquid and` destroy the pumping vacuum) which is dependent on the rateof pumping, the size of the suction pipe, and other factors. Sincecavitation becomes effective before the level of the liquid reaches thebottom of lthe suction pipe, and removalof liquid Ibelow such point isalmost4 impossible, aconsiderable quantity of liquid remains inthecompartment, asthe residual cargo. In addition whenever cavitationbreaks through and destroys the vacuum, pumping not only stops, but itissubstantially impossible to reprime and start pumping again.

The evil of cavitation in emptying tankerbarges is one of the primereasons for residual cargo. V present problem, largely through thegeneral adoption of the unloading procedure, in which the It has .beenlessened to the point of lthe' barge is partially emptied on asubstantially even keel, and then is subsequently emptied progressivelyfrom end to end. In` this manner, as one end of the barge is emptied, itfloats more buoyantly and the barge is longitudinally tilted. Bypositioning the suction pipes adjacent the tank Walls and so emptyingthe barge as to cause it to tilt toward the pipes and adjacent tankwalls, the liquid in each compartment ovvs toward the tank wall, andremoval is thereby assisted. `But even in the use of this unloadingprocedure the problem of residual cargo continues to exist, and thisinvention is directed to the solution of that problem, regardless of theprocedure under which it arises.

The basic means by which this solution is accomplished is in the noveland useful sump keel which is provided for a vessel such as a tankerbarge. If an attempt was made to provide an individual sump for eachtank the result would be that a tremendous drag, seriously impeding thepassage of the barge, would be created. In this invention all of thebenets obtainable from individual sumps are achieved without increase ofdrag or sacrifice to the speed of the vessel, and at the same timeacquiring other andfurther benets as will become apparent hereinafter.

The objects of this invention are:

To provide means facilitating the maximum effective use of cargo spacein a tanker vessel;

To provide means for minimizing residual cargo, in vessel unloading;

To provide means concentrating the liquid adjacent the suction pipe,without substantially increasing the drag of the vessel;

To provide a tanker vessel having a sump keel extending longitudinallyof the vessel, and adapted to receive and concentrate liquid adjacentthe suction pipe;

To provide suction pipes, for use with tanker vessels adapted forlongitudinal tilting during unloading, the pipes being beveled at theirlower ends in substantial parallelism with liquid level at maximum tiltof the vessel;

To provide tanker vessels having sump keels and beveled suction pipes,cooperatively positioned to substantially prevent cavitation and toassure maximum effective use of tank space in such vessel; and

To provide a sump adapted tothe dual purpose of facilitating pumping andacting as a keel.

The means by which the foregoing and other vobjects of the invention areaccomplished, and the manner of their accomplishment, will be readilyunderstood on reference to the accompanying specication and to thedrawings, in which a typical tanker barge, including the improvements ofthis invention, is illustrated.

In the drawings:

Fig. 1 is a plan view of the tanker barge, with the deck partiallybroken away to show the interior construction.

Fig. 2 is a sectional elevation, taken as along the line II-II of Fig.1.

Fig. 3 is a sectional elevation, as along the line III-III of Fig. 2.

Fig. 4 is a fragmental sectional view on an enlarged scale, taken as onthe line IV-IV of Fig. 3; and

Fig. 5 is a fragmental sectional View on a further enlarged scale, takenas on line-V-V of Fig. 4.

Referring now to the drawings in which the various parts are indicatedby numerals:

The tanker barge comprises a hull II and a deck I2. Hull II includesside plates I3 and I4, and bottom plate I5, the bottom plate beingcurved upwardly at the front to join deck I2 and form the bow of thebarge, and being similarly curved upwardly at the rear of the barge tomeet the deck and form the stern. Deck I2 extends from bow to stern andis secured to bottom plate I5 along each junction and is also secured toside plates I3, I4, so as to cover the hull.

I-Iull II is subdivided into a plurality of compartmentsor tanks I1 by alongitudinal tankwall I9, and a plurality of transverse tank walls 2l.These tank walls extend vertically from bottom plate I5 to deck I2, andare secured thereto in usual manner, as by angle irons 23, 24, or inother desired manner. Tank wall I9 extends from bow to stern and issecured to each in desired manner, as by angle irons 25, and tank walls2I extend from side plate to side plate and are similarly secured inposition as by angle irons 26.

As shown'tank wall 2I divides the tanks I1 into parallel rowslongitudinally, a port row and a starboard row. Each of the tanks I1 ispreferably provided with a manhole 21, having a removable cover for usein iilling the tanks or for cleaning or for supervision of liquidwithdrawal or other operations.

According to the present invention, underlying each row of tanks, thereis a sump keel, the port keel being 29, and the starboard keel SI. Eachof the sump keels comprises a substantially U- shaped channel section,exten-ding from end to end of the vessel, and curving symmetrically withbottom plate I5 at both stern and bow. Keels 29, 3I are throughout theirlength preferably secured to and depended from bottom plate I5, as at33, 35. Bottom plate I5 is interrupted adjacent the points of connection33, 55, so as to leave the channels 29, 3i open for the entry of theliquid of tanks I1. It will be noted that a portion of the channel keel29 or 3i underlies each of tanks I1. The keels are interrupted at eachof the transverse tank walls 2|, tank walls 2I having portions 31extended into the channel keel, and blocking the channel keels toprevent flow of liquid past tank walls 2 I, or between tanks I1. In thismanner there is no danger of intermingling of tank contents which wouldprove of particular importance in the event that liquids of varyingcharacteristics were carried in the individual tanks.

Emptying of the vessel is accomplished through customary pumping, as bya pump 39, shown here mounted on the deck I2 of the barge, but which mayand very often is mounted on the wharf (not shown) or other point ofvantage on the shore. In the set-up illustrated, 4I, 43 are longitudinalheaders communicated with pump 39 through T-pipe 45. It will be notedthat T- pipe 45 is provided with capped extensions 41, 48, and thatheaders 4I, 43, terminate in T-pipe 49, which is provided with similarcapped extensions These extensions are provided to accommodate a. pumpinstalled on shore or wharf, in the most convenient position, any of theextensions being adapted if connected to a pump to permit withdrawaltherethrough of the barge contents.

Connected to headers 4I, 43 are suction pipes 5I, each tank I1 having anindividual pipe 5I inserted therein through a suitable opening in deckI2. Each pipe 5I is suitably valved as by valves 53, to permitindividual cutoff as desired. It will be noted that while two headers4I, 43 are shown, a single header might be satisfactorily employed.

A pipe 5I is positioned in each tank I1 adjacent a transverse tank wall2|, all pipes 5I being similarly positioned in their respective tanksI1. The lower end 55, of each pipe 5I, is inserted in the portion of theSump keel underlying the individual tank I1. Pipe end is also preferablybeveled, as at 51, and the pipe so turned that the higher edge of thebevel is toward an adjacent tank wall 2|.

In general the construction of the barge is indicated of customary type,and is not fully discussed herein. The hull I I is assembled, and thechannel keels 29, 3I are welded to bottom plate I5. Plate I5 may then becut out inside to open the tops of the channels. It will be noted,however, that the bottom plate I5 may be cut before the channel keels29, 3| are positioned, or as above stated, after keel positioning, or innew construction individual plates of width adapted to extend to thechannel, may be used without departing from the scope hereof.

After the hull and keels are assembled and joined, suitable cross beams,as beams 59, may be placed, if desired, to laterally strengthen thebarge, and suitable deck beams, as beams 6 I may be secured from sideplate to side plate to provide suitable deck support at desired decklevel. The longitudinal and transverse tank walls'I9, 2| are set up inusual manner, but have portions 31 extending into channel keels 29, 3Ito block the channel keels as described. Deck I2, with manholes 21, maythen be laid on beams 6I, and secured to beams 6I, to side plates I3,I4, and to the upwardly turned ends of bottom plate I5, fore and aft.

The pipe system may be set up, suction pipes 5I inserted throughsuitable openings in deck I2 into tanks I1, valves 53 attached, andheaders 4I, 43 mounted and connected into T-pipes 45, 49, all incustomary fashion. When pipes 5I are prepared for insertion into tanksI1, lower portions 55 are preferably beveled as at 51, to provide abevel compensating for the tilt of the vessel during unloading, thisbevel being such that the bottom end of the pipe is level, as the levelof the last liquid in the tank approaches the end of the pipe. Whenpipes 5I are inserted they are positioned so that the higher edge ofbevel 51 is toward an adjacent tank wall. Lower portion 55 is introducedinto channel keel 29, in each of the port tanks and into channel keel 3|in each of the starboard tanks and is extended downwardly near thebottom of the channel.

In operation, during unloading of the tanker barge, all valves 53 areusually opened at the beginning of pumping and all tanks l1 partiallyemptied, usually about half way. When the desired point has beenreached, the emptying is completed in a progression from end to end ofthe barge. Thus all valves 53, except those for the suction pipes of thetanks nearest the end chosen for beginning of the progression, areclosed, and pumping withdrawal is had from those tanks until theircontents are exhausted. In each instance it is desired to begin theprogression at-the end desired to be first lightened to cause the bargeto tilt toward the suction pipes. In the instance illustrated, theprogressive withdrawal would be begun with tanks l'l-A (Figs. 1 and 2),the Valves 53-A for suction pipes I-A, remaining open until the contentsof tanks I'i-A is exhausted. As the tanks l'I-A are emptied they becomemore buoyant and float higher, tending to tilt the barge, so that liquidin tanks II-A tend to flow toward tank wall 2 I A, to maintain pumpingdepth as far as possible. The 1iquid is drawn by pipe 5l-A and tends tocollect in channels 29, 3| adjacent Walls ZI-A. Thus the liquid willflow into the channel which acts as a sump and the bottom of the tanksII-A will be cleared. As the channels have substantial depth, cavitationis substantially prevented through the maintenance of a pumping level inthe channel after the remainder of the tank has been emptied, and theresidual liquid is reduced to a minimum.

As emptying of tanks I'l-A is completed valves 53--B, for suction pipes5|-B, are opened and tanks Il--B are emptied in manner similar to thatjust described. This procedure is repeated progressively through thelength of the barge, until all the tanks are emptied.

The tilt of the vessel during cargo discharge is illustrated in Fig. 4,and the manner in which the liquid flows into the channel and towardtank wall 2l is shown. The bevel 51 of the pipe 5l is formed along aline substantially parallel with the liquid surface at maximum tilt inthe tank I'I in which the pipe is inserted. The angle of bevel 51 willpreferably vary, depending on the position of the tank in the barge.'Ihat is the angle of the bevel of pipe 5I--A, being in tank ll-A wherethe least tilt would occur, Would be less than the angle of the bevel ofpipe 5|-X in tank l'l-X where the tilt would be greater. The bevels 51are of importance in assisting materially in preventing cavitation, bypermitting the level of liquid to be lowered further down pipes 5l,before the seal is broken. The provision of parallelism of the line ofbevel with the liquid level provides an even withdrawal of the maximumamount of liquid from each tank.

It will be noted that as channel keels 29, 3l underlie cross beams 59,the beams do not interfere with the ow of liquid toward the tank wallsin the channels, while in the absence of the channel keels the beamswould have to have openings for liquid passage, if serious interferencewas to be avoided.

It will also be noted that existing barges may readily be changed toinclude this invention by securing channel keels of the type describedto the bottom of such barges, and cutting the bottom plates to provide aready entrance opening for liquid, into which a suction pipe might beinserted.

It will also be noted that the continuous keel will not impede thelongitudinal motion of the barge as would a series of sumps, but thatthe sump keel acts as a true keel, and by its depth beneficiary limitslateral movement of the barge.

It will be understood that the embodiment of the invention shown anddescribed is intended as typical, and that the sump keel inay be usedwith other type vessels without departing from thescope of thisinvention, and that the shape of the sump keel may be varied withoutdeparting from the scope of this invention.

I claim:

l. In a vessel, which includes a plurality of tanks having substantiallynat bottoms and adapted to carry liquid, a keel comprising asubstantially channel-shaped member depended below and extending alongsaid tank bottoms, said keel being divided into a plurality of sections,each corresponding to a said tank and being communicated with theinterior of said tank to serve as a sump for the liquid carried thereby.

2. In a vessel, which includes a plurality of tanks having substantiallyflat bottoms and adapted to carry liquids, and means for emptying saidtanks, including suction pipes, each said tank having one of said pipesinserted therein, a keel, comprising a substantially channelshapedmember depended below and extending along said tank bottoms, said keelbeing divided into a plurality of sections, each said sectioncorresponding to a said tank and being communicated with the interior ofsaid tank, to serve as a sump for liquid therein, each said pipe beingextended into the sump section related to the tank in which said pipe isinserted.

3. A substantially flat bottomed barge, having its interior segregatedinto a plurality of tanks adapted for liquid transportation, said bargehaving a member of substantially U-shaped cross section depended fromits bottom and longitudinally extending from end to end thereof, theinterior of said member being segregated into sections correspondingwith said tanks, each said tank being communicated with a said section,whereby said sections serve as sumps for theirrelated said tanks, theexterior of said member being continuous to minimize lateral movement ofsaid barge.

4. A vessel, which includes a plurality of tanks, adapted to carryliquid, arranged in longitudinal parallel rows, each said tank rowhaving, depended therebelow and extending along the bottom thereof, akeel, comprising a substantially channel-shaped member, each said keelbeing segregated into sections, each corresponding with a said tank ofits related said row and being communicated with the interior of itsrelated said tank to serve as a sump for the liquid therein.

5. A vessel, which includes a plurality of tanks adapted to carryliquid, arranged in longitudinal parallel rows, and means for emptyingsaid tanks, including suction pipes, each said tank having one of saidpipes inserted therein, each said vtank row having, depended therebelowand extending along the bottom thereof, a keel, comprising asubstantially channel-shaped member, each said keel being segregatedinto sections each corresponding with a said tank of its related saidrow and being communicated with the interior of its related said tank toserve as a sump for the liquid therein, the pipe inserted in each saidtank being extended into its related said keel section.

6. In combination with a vessel having a plurality of tanks for carryingliquid, said vessel being adapted to be emptied progressively from endto end and to longitudinally tilt as said emptying progresses, means foraccomplishing said emptying which includes a plurality of suction pipes,each said tank having one of said pipes inserted therein, each said pipehaving its lower end beveled along a line substantially parallel withthe liquid level in said vessel upon tilting.

7. In combination with a vessel having a plurality of tanks for carryingliquid, said vessel being adapted to be emptied progressively from endto end and to longitudinally tilt as said emptying progresses, sumpsections, each said tank having a said section related thereto, andmeans for emptying said tanks which includes a plurality of suctionpipes, having their respective lower ends beveled along a linesubstantially parallel With the liquid level in said vessel upontilting, each said tank having one of said pipes inserted therein withthe bevel of said pipe extended into the said sump section related tothe tank.

8. In combination with a vessel, having a plurality of tanks forcarrying liquid, said vessel being adapted to be emptied progressivelyfrom end to end, and longitudinally tilt as said emptying progresses,means for accomplishing said emptying which includes a plurality ofsuction pipes, each said tank having one of said pipes inserted therein,each said pipe having its lower end beveled, the respective said pipebevels varying from tank to tank, whereby the line of bevel of each saidpipe is substantially parallel with the liquid level of its related saidtank at maximum tilt thereof.

JOHN PREUSS.

